Commuters in the Bridgeport metropolitan area took an extra week of "vacation" last year, only they spent it sitting in traffic.

The achingly slow crawls south near sunrise and north at night may be nothing new for commuters in southwestern Connecticut, but they are getting worse.

So says a report issued Wednesday by INRIX, a traffic services provider based in Washington, that ranked traffic in the Bridgeport metropolitan area as the sixth worst in the nation in 2012.

All that time sipping coffee and listening to talk radio behind the wheel added up to an average of 39 hours per commuter last year, according to the report.

And drive-time is only getting drearier.

According to data released by INRIX, commuters found themselves in traffic 16 percent longer in the first three months of 2013 than they did in the first quarter of 2012.

None of that is news to Dave Salpietro, a commercial roofer from Norwich who works out of Bridgeport and stopped to gas up at the Mobil station on Interstate 95 north in Fairfield on Wednesday.

Working at times as far north as Massachusetts and as far south as New Jersey, he's gotten painfully familiar with the ebb and flow of I-95's congestion over the years.

"If I go to work and I head north, it's not a problem. If I've got to head south -- can't do it," he said. "Once you start hitting 6:30 (a.m.), 7 o'clock at exit 25 in Bridgeport -- that's it."

But that's actually a good thing, at least as far as the authors of the report are concerned.

Though the effect can be aggravating, the cause of increased traffic is one the metro area and country have been clamoring over for years: economic growth.

Ultimately, as more people find work, more commuters have to hit the highway and traffic congestion increases.

Across the country, congestion on commuter corridors in each of the first three months of this year increased over levels recorded in 2012, which falls in line with a 1.3 percent increase in employment over that time, the report maintains.

"While bad news for drivers, the gains we've seen in the U.S. ... are cause for some optimism about the direction of the economy," Bryan Mistele, INRIX president and chief executive officer, said in a news release.

Wondering which are the worst times to drive in the area?

If you're heading north on I-95 from 5 to 6 p.m. on Fridays and driving the 22.2 miles from exit 2 in Greenwich to exit 21 in Fairfield, you will have about a 40-minute delay, according to data compiled by INRIX. Your speed will be just over 20 mph, it said.

That trip made the I-95 north corridor in southwestern Connecticut the 42nd most congested in the country in 2012.